Treatment of meats with ionising radiations. III.—Radiation pasteurisation of whole eviscerated chicken carcasses

Abstract

Whole eviscerated chicken carcasses were irradiated with y-radiation from 6oCo, using varying doses up to I Mrad. Changes in quality were assessed by submitting samples to a laboratory panel and to a domestic consumer panel ; and the effect of radiation in prolonging the period required for microbial spoilage under chilled conditions of storage was studied. When the meat was stored a t 1 ' c, a dose of 0.8 Mrad gave a five-fold extension of the time required for putrefactive spoilage, and the flavour changes after such a dose were usually not noticed in roasted chickens. The quality of the irradiated carcasses tended to deteriorate during storage, however, and this loss of quality was apparent when the chickens were stored for more than about one and a half times the period required for spoilage of untreated carcasses stored at I ' c. The deterioration is not due to oxidative rancidity of the lipids. Experimental Chicken caycassesThese were obtained from a mechanised packing plant, where the birds were plucked mechanically, eviscerated on a processing line, washed, and then cooled in ice slush for at least 2 h. Carcasses weighing 2-2$ lb. were selected, allowed to drain, then trussed and packed in a close-fitting polyethylene bag on the processing line. The wrapped carcasses were placed in larger loose-fitting polyethylene bags (Visqueen Layflat tubing, 0.05 mm. thick) which were heat-sealed. The carcasses were stored on ice before they were irradiated, usually within I or 2 days. Treatment of the carcasses with chlortetracycline or ascorbic acid was effected by cooling them in ice slush containing 10 p.p.m. chlortetracycline or 1% ascorbic acid for 2 h. instead of ordinary ice slush.In experiments on the effects of storage in the presence or absence of oxygen, the unwrapped carcasses were placed in lacquered AIO cans (15 cm. diam. x 17.5 cm. high) and excessive free movement of the carcasses prevented by inserting some cellulose wadding. The cans were sealed at atmospheric pressure ; to remove oxygen, a small hole was punched in one end and the can evacuated (to about 10 cm. Hg pressure) and flushed with oxygen-free nitrogen. The cycle was repeated three times and the hole soldered over at atmospheric pressure. As before, the cans were held on ice until they were irradiated, allowing ample time for residual traces of oxygen in the nitrogen-packed samples to be removed by metabolic processes.The carcasses were then packaged as described above.

Effect of irradiation and packaging type on sensory quality of chill‐stored turkey breast fillets

“…When cooked the barrier-wrapped samples were still described as 'pink', 'pink inside', 'uneven colour' and 'undercooked' and dissociated from all other samples. In contrast to the results of Coleby et al (1960) with chicken, the pinkness in the raw samples was very acceptable to the panel, and these samples were preferred, but after cooking pinkness was not liked.…”

“…This was noted in chicken by Coleby et al (1960) and Rhodes (1965). At storage of 1 day, the irradiated barrier-wrapped samples were more pink than the polythene wrapped; after 21 days the polythene wrapped samples were associated with descriptors such as brown, dull, old, soggy (the same as non-irradiated) whilst barrier-wrapped samples were still intensely pink.…”

“…As there was very little microbiological growth these odours are presumably chemical changes in the meat induced by irradiation. Taub et al (1979) suggested that this is due to protein denaturation which produces sulphurous compounds; similar odours were detected in chickens by Coleby et al (1960) after storage in nitrogen. However the odour descriptors given in the present study are not really sulphurous notes and a further explanation is sought.…”

Effects of Refrigerated Storage, pH Adjustment, and Marinade on Color of Raw and Microwave Cooked Chicken Meat

“…Pink color gives the impression that the product is undercooked, and is occasionally found in freshly cut poultry products after cooking. The causes for pink meat, according to the literature, are as follows: 1) carbon monoxide or nitric oxide generated in gas-fired ovens (Pool, 1956); 2) irradiation pasteurization (Coleby et al, 1960;Mead and Roberts, 1986); 3) nitrates or nitrites in the bird's diet (Froning et al, 1967); 4) different concentrations of muscle myoglobin in meat (Froning et al, 1968a); 5) use of spray-dried albumin as a food additive (Froning et al, 1968b); 6) changes in endpoint cooking temperature and storage (Helmke and Froning, 1971); 7) higher cytochrome levels in muscle as a result of preslaughter stress (Babji et al, 1982); 8) inhalation of gases by birds during transport (Froning, 1983); 9) nitrites in processing plant water supplies or from curing procedures (Brant, 1984); 10) leakage of refrigerant gases in the processing plant (Everson, 1984); 11) replacement of muscle nitrosyl pigments with reduced and denatured hemochromes in meat (Cornforth et al, 1986); 12) microbial conversion of nitrates to nitrites during storage (Ahn and Maurer, 1987); and 13) incomplete denaturation of myoglobin during cooking (Trout, 1989). Schmidt and Trout (1984) and Trout (1989) indicated that when cooked to the same internal temperature, beef, pork, and turkey muscle with pH greater than 6.0 became more red in color than muscle with pH 5.5.…”

Effects of High-Energy Electron Irradiation of Chicken Meat on Salmonella and Aerobic Plate Count

“…Interest in making wider use of this tool in food technology has been shown by the scientific community, industry, and federal agencies (Institute of Food Technologists, 1983;Engel, 1985). The use of irradiation to increase microbiological shelf-life and ensure the safety of various poultry products has received considerable attention (Coleby et al, 1960;Rhodes, 1965;Mercuri et al, 1967;Idziak and Incze, 1968;Kahan and Howker, 1978). Most of the published research concerned with the nutritional, microbiological, and toxicological aspects of fresh red meat or poultry meat exposed to ionizing radiation has been conducted under conditions suitable for application in commercial operations using gamma radioisotopes (Thomas and Josephson, 1970;deGroot et al, 1976;Howker et al, 1976; Scientific Article Number A-4848.…”